20 KB is the upper limit for signatures on several exam forms — SSC CGL 2026 and IBPS PO 2026 both ask for 10–20 KB. Many forms ask for a scanned signature between 10 and 20 KB, and some also use 20 KB as the upper limit for a small photo. This page is preset to 20 KB, outputs JPG, and runs in your browser so the image never leaves your phone.
Where you'll meet a 20 KB limit
Signature uploads are the classic case. For example, the SSC CGL 2026 notice asks for a signature of 10–20 KB, and the IBPS PO 2026 notification asks for a 140 × 60 px signature of 10–20 KB. Plenty of state and university forms use a similar range.
If a form gives a minimum as well as a maximum, compressing alone isn't enough — a very small file might fall below the minimum. Use Resize Image or the exam tool, which set exact pixels and keep the file between both limits.
Compressing a phone photo of your signature
- Sign on plain white paper with a black pen (some forms insist on black ink).
- Take the photo from directly above in daylight, without your hand's shadow.
- Crop so the signature fills most of the frame with a little margin — Crop Image has a 3:1 signature shape.
- Add it here and tap Compress to under 20 KB.
- Zoom in on the result: the strokes should be smooth, not broken.
How quality is kept as high as possible
The compressor uses a binary search on JPEG quality: it tests a quality level, checks the size, and halves the gap until it finds the highest quality under 20 KB. That's better than a fixed 'low quality' setting, which often shrinks the file far more than needed.
Only when the lowest sensible quality is still above 20 KB does it scale the image down, keeping proportions. The final file is under 20,000 bytes, safe for portals that count 1 KB as 1,000 or 1,024 bytes.
Batch: compress photo and signature together
You can add up to 30 images at once and they'll all be compressed to the same target. That's handy for a set of document photos. If your photo and signature have different limits, run them separately.